Answer: horizontally compressing the graph of f(r) by a factor 99.
Explanation:
When we replace r in the function f(r) with 99, it means that we are compressing the graph of f(r) horizontally by a factor of 99. This is because the entire graph of f(r) will be squeezed horizontally into a smaller space, giving the appearance of a compressed graph. Stretching or compressing the graph vertically would change the range of the function, not the domain, and therefore would not affect the value of f(99).